4. BALANCE SHEET DETAIL - Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Prepaid expenses and other current assets:
Prepaid tooling and masks	$ 707	$ 535
Prepaid income taxes	79	39
Escrow deposit		1,000
Other receivables	211	321
Other prepaid expenses and other current assets	937	605
Total prepaid expenses and other current assets	$ 1,934	$ 2,500